Light emitting diode package, circuit board for light emitting diode package and method of manufacturing the same

ABSTRACT

A circuit board for a light emitting diode package improved in heat radiation efficiency and a manufacturing method thereof. In a simple manufacturing process, insulating layers are formed by anodizing on a portion of a thermally conductive board body and plated with a conductive material. In the light emitting diode package, a board body is made of a thermally conductive metal. Insulating oxidation layers are formed at a pair of opposing edges of the board body. First conductive patterns are formed on the insulating oxidation layers, respectively. Also, second conductive patterns are formed in contact with the board body at a predetermined distance from the first conductive patterns, respectively. The light emitting diode package ensures heat generated from the light emitting diode to radiate faster and more effectively. Additionally, the insulating layers are formed integral with the board body by anodizing, thus enhancing productivity and durance.

CLAIM OF PRIORITY

This application claims the benefit of Korean Patent Application No.2006-18861 filed on Feb. 27, 2005 in the Korean Intellectual PropertyOffice, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a light emitting diode package, moreparticularly, in which insulating layers are formed by anodizing on aportion of a thermally conductive board by anodizing and plated with aconductive material, thereby simplifying its manufacturing process andimproving heat radiation efficiency, a circuit board for a lightemitting diode and a manufacturing method thereof.

2. Description of the Related Art

A backlight for a mobile phone, a navigation system and a personaldigital assistant (PDA) mainly adopts a light emitting device using alight emitting diode which is long in useful life and can be reduced insize. The light emitting device using the light emitting diode is moreadvantageous than a light emitting device using a cold cathodefluorescent lamp (CCFL). That is, the light emitting diode (LED) isenvironment-friendly, quick to respond to with a rate of several nanoseconds, thus assuring higher color reproductivity. Also, the LED isadjustable in its light amount to arbitrarily alter brightness and colortemperature.

The light emitting device using the light emitting diode is largelyconstructed of a circuit board having a current pattern formed thereon,and a light emitting diode disposed on the circuit board. Recently, witha high-output light emitting diode commercially viable, there has arisena demand for the circuit board capable of radiating heat generated fromthe light emitting diode more effectively.

A conventional light emitting device using a light emitting diode willbe explained with reference to the accompanying drawings.

FIG. 1 is an exploded perspective view illustrating the conventionallight emitting device.

As shown in FIG. 1, the light emitting device 1 includes a circuit board3 with a current pattern formed thereon, a light emitting diode 6disposed on the circuit board 3 and a reflective member 2 for guidingdirection of light from the light emitting diode.

The circuit board 3 is made of an insulating material and a pair ofelectrodes 4 a and 4 b are formed at opposing sides to be electricallyconnected to the outside. Conductive patterns 5 a and 5 b of e.g., acopper foil are formed on a top surface of the circuit board 3. Theconductive patterns 5 a and 5 b are electrically connected to theelectrodes 4 a and 4 b, respectively and extended toward a center of thetop surface of the circuit board body 3. Moreover, fixed electrodepatterns 7 a to 7 d made of e.g., the copper foil, are provided at eachcorner of the top surface of the circuit board 3. Here, an insulatingfilm 8 may be provided on the electrodes 4 a and 4 b and the conductivepatterns 5 a and 5 b to insulate the top surfaces thereof.

The reflective member 2 is made of a resin such as a heat-resistanthigh-performing plastic or a metal such as copper and aluminum. Thereflective member 2 has a reflective through hole 2 a perforated in acentral portion thereof to seat the light emitting diode 6. An innerwall of the reflective through hole 2 a is bright-plated with silver ornickel to enhance reflectivity of light emitted from the light emittingdiode 6. Here, the reflective member may be bright-plated on all sidesthereof.

The reflective member 2 and the circuit board body 3 are sizedsubstantially identical to each other.

The light emitting diode 6 is disposed in a mounting area 3 a, i.e., thecentral portion of the top surface of the circuit board 3. Although notillustrated, an anode and a cathode are electrically connected to theconductive patterns 5 a and 5 b, respectively.

Accordingly, current applied to the circuit board 3 flows to the lightemitting diode 6 through the electrodes 4 a and 4 b, and the conductivepatterns 5 a and 5 b so that the light emitting diode 6 emits lightupward.

Heat generated from the light emitting diode 6 is radiated through thecircuit board 3, that is, an insulating member connected to an undersidesurface of the light emitting diode 6. In general, since the insulatingmaterial is very low in thermal conductive efficiency, the conventionallight emitting device 1 structured as above cannot radiate heat from thelight emitting diode 6 effectively.

In an attempt to overcome the problem, a circuit board has beenproposed, in which a through hole is perforated in an area where thelight emitting diode 6 is disposed, and filled with a thermal conductivematerial. Yet this structure complicates a manufacturing process, andlimitedly enhances heat radiation efficiency due to contact of thethermal conductive material with only a portion of the underside surfaceof the light emitting diode.

In addition, in the circuit board body 3 configured as above, theelectrodes 4 a and 4 b, conductive patterns 5 a and 5 b and theinsulating layer 8 should be fabricated separately. This renders themanufacturing process cumbersome, increases manufacturing costs andsignificantly undermines productivity.

SUMMARY OF THE INVENTION

The present invention has been made to solve the foregoing problems ofthe prior art and therefore an aspect of the present invention is toprovide a circuit board for a light emitting diode package whichradiates heat generated from a light emitting diode more effectively,reduces manufacturing costs through a simplified manufacturing process,and boosts productivity, and a manufacturing method thereof.

According to an aspect of the invention, the circuit board for the lightemitting diode package having a light emitting diode disposed thereon,including a board body made of a thermally conductive metal; insulatingoxidation layers formed at a pair of opposing edges of the board body;first conductive patterns formed on the insulating oxidation layers,respectively; and second conductive patterns formed in contact with theboard body at a predetermined distance from the first conductivepatterns, respectively.

The board body is made of one selected from a group consisting ofaluminum, titanium, tantal, magnesium, hafnium and alloys thereof.

The insulating oxidation layers are formed by anodizing.

The insulating oxidation layers have a uniform thickness.

Alternatively, the insulating oxidation layers are formed on surfaces ofthe opposing edges of the board body including upper and lower surfacesand flank surfaces thereof.

The insulating oxidation layers have both end portions thereof locatedin a top surface of the board body extending toward a central line ofthe board body, which is substantially parallel with the opposing edges.

According to another aspect of the invention, the method formanufacturing a circuit board for a light emitting diode packageincludes:

perforating at least two through holes in a board body made of athermally conductive metal;

forming insulating oxidation layers in predetermined surface areas ofthe board body, which are adjacent to upper and lower ends of thethrough holes, and inner wall surfaces of the through holes,respectively;

forming first conductive patterns on the insulating oxidation layers andsecond conductive patterns between the first conductive patterns; and

cutting the board body in such a fashion that the first conductivepatterns are disposed at opposing edges of the board body and the secondconductive patterns are located in a central portion of the board body.

The through holes are formed in at least two rows in the perforatingstep, and each of the insulating oxidation layers is formed to surroundthe through holes in each of the rows in the step of forming theinsulating oxidation layers.

The insulating oxidation layers are formed by anodizing.

The board body is made of one selected from a group consisting ofaluminum, titanium, tantal, magnesium, halfnium and alloys thereof.

According to further another aspect of the invention, the light emittingdiode package includes a board body made of a thermally conductivemetal; insulating oxidation layers formed at opposing edges of the boardbody; first conductive patterns formed on the insulating oxidationlayers, respectively; second conductive patterns formed in contact withthe board body at a predetermined distance from the first conductivepatterns, respectively; a light emitting diode disposed on the secondconductive patterns and electrically connected to the first conductivepatterns; and a transparent resin covering the light emitting diode.

The board body is made of one selected from a group consisting ofaluminum, titanium, tantal, magnesium, halfnium and alloys thereof.

The insulating oxidation layers are formed by anodizing.

The insulating oxidation layers have a uniform thickness.

Alternatively, the insulating oxidation layers are formed on surfaces ofthe opposing edges of the board body including upper and lower surfacesand flank surfaces thereof.

The insulating oxidation layers are formed such that both end portionsthereof located in a top surface of the board body are extended toward acentral line of the board body, which is substantially parallel with theopposing edges.

According to further another aspect of the invention, the method formanufacturing the light emitting diode package includes:

perforating at least two through holes in a board body made of athermally conductive metal;

forming insulating oxidation layers in predetermined areas of the boardbody, which are adjacent to upper and lower ends of the through holes,and inner wall surfaces of the through holes, respectively;

forming first conductive patterns on the insulating oxidation layers,respectively, and second conductive patterns between the firstconductive patterns;

disposing light emitting diodes on the second conductive patternsbetween the through holes, respectively, and electrically connecting thelight emitting diodes with the first conductive patterns;

coating a transparent resin to cover the light emitting diodes; and

cutting the board body to separate the light emitting diodes into eachunit

The through holes are formed in at least two rows in the perforatingstep, each of the insulating oxidation layers is formed to surround thethrough holes in each of the rows in the step of forming the insulatingoxidation layers, and each of the light emitting diodes is disposedbetween two of the through holes in different rows in the step ofdisposing the light emitting diodes.

The transparent resin is formed of a strip to entirely cover the rows ofthe light emitting diodes.

The insulating oxidation layers are formed by anodizing.

The board body is made of one selected from a group consisting ofaluminum, titanium, tantal, magnesium, halfnium and alloys thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of thepresent invention will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is an exploded perspective view illustrating a conventional lightemitting device;

FIGS. 2 to 7 are plan views sequentially illustrating a method formanufacturing a light emitting diode package according to the invention;

FIG. 8 is a plan view illustrating a light emitting diode packageaccording to the invention;

FIG. 9 is a side cross-sectional view illustrating a light emittingdiode package according to the invention;

FIG. 10 is a side cross-sectional view illustrating a light emittingdiode package according to a second embodiment of the invention;

FIG. 11 is a side cross-sectional view illustrating a light emittingdiode package according to a third embodiment of the invention;

FIG. 12 is a side cross-sectional view illustrating a circuit board fora light emitting diode package according to an embodiment of theinvention;

FIG. 13 is a side cross-sectional view illustrating a light emittingdiode package according to a fourth embodiment of the invention; and

FIG. 14 is a plan view illustrating a light emitting diode packageaccording to a fifth embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Exemplary embodiments of the present invention will now be described indetail with reference to the accompanying drawings.

FIGS. 2 to 7 are plan views sequentially illustrating a method formanufacturing a light emitting diode package according to the invention.

To manufacture a circuit board for a light emitting diode packageaccording to the invention, first, as shown in FIG. 2, through holes 110are formed in rows in a board body 100 made of a thermally conductivemetal. As shown in FIG. 3, insulating oxidation layers 120 are formed tosurround the through holes 110 in each of the rows.

Preferably, the insulating oxidation layers 120 are provided,respectively, as a strip extending on the row of the through holes 110.This allows the insulating oxidation layers 120 to surround the throughholes 110 in each of the rows through a single process. Preferably, theinsulating oxidation layers 120 are formed more easily by anodizing. Theanodizing obviates a need for separate manufacturing and bonding of theinsulating oxidation layers 120, thereby simplifying a manufacturingprocess. Also, the anodizing allows the insulating oxidation layers 120to be formed integral with the board body 100, thereby enhancingdurability. The anodizing is generally utilized in forming an oxidationfilm, which thus will be explained in no more detail.

Moreover, to form the insulating oxidation layers 120 by the anodizing,the board body 100 preferably is made of one selected from a groupconsisting of aluminum, titanium, tantal, magnesium, halfnium and alloysthereof.

FIG. 4 is a cross-sectional view illustrating the board body 100 cutalong the line A-A of FIG. 3. As shown in FIG. 4, the insulatingoxidation layers 120 are provided adjacent to upper and lower openingsof the through holes 110 and in inner walls thereof, respectively. Here,top surfaces of the insulating oxidation layers 120 define a regionwhere first conductive patterns 210 (not illustrated) will be formedlater. Thus, the insulating oxidation layers 120 have a uniformthickness from the inner walls of the through holes 110. The insulatingoxidation layers 120 can be varied in thickness thereof.

The insulating oxidation layers 120, as shown in this embodiment, mayextend vertically through an entire adjacent area surrounding thethrough holes 100 so that the insulating oxidation layers 120 have auniform thickness from the inner walls of the through holes 110.Alternatively, as described above, the insulating oxidation layers 120may be provided adjacent to upper and lower openings of the throughholes 110 and in inner walls thereof. Here, the insulating oxidationlayer 120 formed only adjacent to upper and lower openings of thethrough holes 110 and in inner walls thereof will be explained withreference to a separate drawing.

With the insulating oxidation layers 120 formed as described above,first conductive patterns 210 are formed on the insulating oxidationlayers 120, respectively and second conductive patterns 220 are formedbetween the first conductive patterns 210 as shown in FIG. 5. The firstpatterns 210 will have wires joined thereto to supply current to a lightemitting diode 300 (not illustrated) later. Accordingly, to facilitatejoining of the wires, preferably, the first patterns 210 are provided ontop and underside surfaces of the board body 100. Furthermore, thesecond conductive patterns 220 define a region where the light emittingdiode 300 is disposed later, and thus each preferably has a flat topsurface.

The first and second conductive patterns 210 and 220 can be formed bygeneral plating methods or various methods such as metal deposition.Also, other alternative methods can be adopted.

In this embodiment, the first conductive patterns 210 and the secondconductive patterns 210 and 220 are connected to each other at both sideends thereof, merely to facilitate formation of the first and secondconductive patterns 210 and 220. That is, a connecting portion betweenthe first and second conductive patterns 210 and 220 is cut and removedlater so that the first and second conductive patterns 210 and 220 areconsidered as a separate constitution.

In addition, according to this embodiment, the first and second patterns210 and 220 are formed of a strip along each of the rows of the throughholes 110 for the sake of manufacturing convenience and higherproductivity. But the first and second conductive patterns 210 and 220are not limited thereto in a shape thereof. For example, alternatively,the first conductive patterns 210 may be formed around each of thethrough holes 110 and the second conductive patterns 220 may be formedto alternate with the respective first conductive patterns 210.

After the first and second conductive patterns 220 are completed asdescribed above, light emitting diodes 300 are disposed on theconductive patterns 220 formed between two of the through holes 110 indifferent rows. Then the light emitting diodes 300 are electricallyconnected to the first conductive patterns 210 by wires.

The light emitting diodes are disposed by die bonding or eutecticbonding. In the former method, an adhesive such as silver paste,transparent epoxy and solder is coated on the second conductive patterns220 and then the light emitting diodes are disposed thereon,respectively to be heat treated at a predetermined temperature. In thelatter method, the light emitting diodes 300 are subjected to fluxlessor flux eutectic bonding. The light emitting diodes may be disposed byany conventional method for manufacturing the light emitting device.

After the light emitting diodes 300 are disposed, as shown in FIG. 7, atransparent resin 400 is coated to cover the light emitting diodes 300.Then, the board body 100 is cut along a trimming line C to separate thelight emitting diodes 300 into each unit. Here, the transparent resin400 is formed as a strip along each of the rows of the through holes 110in the same manner as the first and second conductive patterns 210 and220 for the sake of manufacturing convenience and higher productivity.However, the transparent resin 400 may be applied individually aroundeach of the light emitting diodes.

The manufacturing method of the light emitting diode package accordingto the invention as just described produces a plurality of lightemitting diode packages through a single process, thereby improvingproductivity. Also, insulating layers are formed not separately as inthe conventional method, but more easily by anodizing. This simplifies amanufacturing process and saves manufacturing costs.

Here, in order to manufacture only the circuit board for use in thelight emitting diode package, the board body 100 is cut along a trimmingline C as shown in FIG. 7, with the insulating oxidation layers 120, andthe first and second conductive patterns 210 and 220 formed as shown inFIG. 5, thereby producing a plurality of circuit boards for the lightemitting diode package through a single process.

FIG. 8 is a plan view illustrating a light emitting diode packageaccording to the invention. FIG. 9 is a side cross-sectional viewillustrating a light emitting diode package cut along the line B-B ofFIG. 8 according to the invention.

As shown in FIGS. 8 and 9, in the light emitting diode package of theinvention, a light emitting diode 300 is connected to a board body 100made of a thermally conductive metal through second conductive patterns220 so that heat generated from the light emitting diode 300 is radiatedoutside through the board body more effectively. Here, preferably, theboard body 100 is made of a high thermal conductive material to furtherboost heat radiation effects. More preferably, the board body 100 ismade of aluminum which is high in thermal conductivity and low-priced.The board body 100 made of aluminum boosts radiation efficiency of heatgenerated from the light emitting diode 300 as just described and allowseasier formation of insulating oxidation layers having a compositionexpressed by Al₂O₃ by anodizing.

Preferably, one of the second conductive patterns 20 is formed on anunderside surface of the board body 100 so that heat can be conducted toanother member or structure, on which the light emitting diode packageis mounted, effectively through the underside surface of the board body100. That is, the underside surface of the board body 100 is madecontact with the mounting member or structure of the light emittingdiode package.

The light emitting diode package according to the invention radiatesheat from the light emitting diode faster and more effectively.Therefore, the light emitting diode package can adopt a low-power lightemitting diode 300 with relatively lower heat radiation amount and ahigh-power light emitting diode 300 with relatively higher heatradiation amount.

FIG. 10 is a side cross-sectional view illustrating a light emittingdiode package according to a second embodiment of the invention.

A transparent resin 400 applicable to the light emitting diode package,as shown in FIG. 9, may have a flat top surface, but alternatively thetop surface thereof may feature various shapes such as a hemisphere asshown in FIG. 10 in order to adjust a light emitting angle of the lightemitting diodes 300.

Shapes and materials of the transparent resin 400 can be varied, andthus will be explained in no more detail.

FIG. 11 is a side cross-sectional view illustrating a light emittingdiode package according to a third embodiment of the invention.

As shown in FIG. 11, in the light emitting diode package of theinvention, a second conductive pattern 220 may be formed on only a topsurface of the board body 100, but not on an underside surface thereof.

Here, when the light emitting diode package is mounted on another memberor structure, the underside surface of the board body 100 is spacedapart from the mounting member, thereby radiating heat from the lightemitting diode 300 by air circulation.

Moreover, the light emitting diode package shown in FIGS. 9 and 10 canbe disposed only on a member having a flat top surface. However, thelight emitting diode package shown in FIG. 11 can be disposed on amember with an uneven top surface.

FIG. 12 is a side cross-sectional view illustrating a circuit board fora light emitting diode package according to the invention. FIG. 13 is aside cross-sectional view illustrating a light emitting diode packageaccording to a fourth embodiment of the invention.

As shown in FIG. 12, the circuit board for the light emitting diodepackage of the invention has insulating oxidation layers 120 thinlyformed in specific surface areas of the board body 100, that is, upperand lower surface areas of the board body 100 adjacent to upper andlower ends of the through holes 110, and inner wall surfaces thereof.Here, the insulating oxidation layers 120 formed adjacent to the upperand lower ends of the through holes 110 should be extended to at least apredetermined length toward a center of the board body 100 as shown inFIG. 11, thus providing a sufficient area for connecting wires of thelight emitting diode 300.

As shown in FIGS. 10 and 11, the insulating oxidation layers 120 with asmall thickness shortens the anodizing process therefor, and enlargesheat conductive area, which is not oxidized, thereby further enhancingheat radiation effects.

FIG. 14 is a plan view illustrating a light emitting diode packageaccording to a fifth embodiment of the invention.

As shown in FIG. 14, in the light emitting diode package of theinvention, the insulating oxidation layers 120 are formed at opposingedges of a board body 100 in such a fashion that both end portions ofthe insulating oxidation layers 120 in a top surface of the board body100 are extended toward a central line of the board body 100, which issubstantially parallel with the opposing edges.

With the both end portions of insulating oxidation layers 120 extendedas just described, first conductive layers 210 on the insulatingoxidation layers 120 can also be extended toward the central line of theboard body 100. This assures more effective use of the insulatingoxidation layers 120. Alternatively, in order to utilize the insulatingoxidation layers 120, the first conductive layers 210 may be formed asshown in the embodiments 1 to 4 or alternatively only may be formed suchthat the both end portions thereof are extended toward the central lineof the board body 100.

The insulating oxidation layers 120, and the first and second conductivepatterns 210 and 220 can be configured variously without being limitedto the embodiments of the invention.

As set forth above, according to exemplary embodiments of the invention,in a light emitting diode package, heat generated from a light emittingdiode can be radiated faster and more effectively. Moreover, the lightemitting diode package is improved in durability due to insulatinglayers formed integral with a board body, and also beneficially adoptsboth a low power light emitting diode and a high power light emittingdiode.

According to the invention, the light emitting diode can be manufacturedthrough a simple process, thereby saving manufacture costs. In addition,a plurality of light emitting diode packages can be manufactured toboost productivity.

While the present invention has been shown and described in connectionwith the preferred embodiments, it will be apparent to those skilled inthe art that modifications and variations can be made without departingfrom the spirit and scope of the invention as defined by the appendedclaims.

1. A circuit board for a light emitting diode package having a lightemitting diode disposed thereon, comprising: a board body made of athermally conductive metal; insulating oxidation layers formed at a pairof opposing edges of the board body; first conductive patterns formed onthe insulating oxidation layers, respectively; and second conductivepatterns formed in contact with the board body at a predetermineddistance from the first conductive patterns, respectively.
 2. Thecircuit board according to claim 1, wherein the board body is made ofone selected from a group consisting of aluminum, titanium, tantal,magnesium, hafnium and alloys thereof.
 3. The circuit board according toclaim 1, wherein the insulating oxidation layers are formed byanodizing.
 4. The circuit board according to claim 1, wherein theinsulating oxidation layers have a uniform thickness.
 5. The circuitboard according to claim 1, wherein the insulating oxidation layers areformed on surfaces of the opposing edges of the board body includingupper and lower surfaces and flank surfaces thereof.
 6. The circuitboard according to claim 1, wherein the insulating oxidation layers haveboth end portions thereof located in a top surface of the board bodyextending toward a central line of the board body, which issubstantially parallel with the opposing edges.
 7. A method formanufacturing a circuit board for a light emitting diode packagecomprising: perforating at least two through holes in a board body madeof a thermally conductive metal; forming insulating oxidation layers inpredetermined surface areas of the board body, which are adjacent toupper and lower ends of the through holes, and inner wall surfaces ofthe through holes, respectively; forming first conductive patterns onthe insulating oxidation layers and second conductive patterns betweenthe first conductive patterns; and cutting the board body in such afashion that the first conductive patterns are disposed at opposingedges of the board body and the second conductive patterns are locatedin a central portion of the board body.
 8. The method according to claim6, wherein the through holes are formed in at least two rows in theperforating step, and each of the insulating oxidation layers is formedto surround the through holes in each of the rows in the step of formingthe insulating oxidation layers.
 9. The method according to claim 7,wherein the insulating oxidation layers are formed by anodizing.
 10. Themethod according to claim 7, wherein the board body is made of oneselected from a group consisting of aluminum, titanium, tantal,magnesium, halfnium and alloys thereof.
 11. A light emitting diodepackage comprising: a board body made of a thermally conductive metal;insulating oxidation layers formed at opposing edges of the board body;first conductive patterns formed on the insulating oxidation layers,respectively; second conductive patterns formed in contact with theboard body at a predetermined distance from the first conductivepatterns, respectively; a light emitting diode disposed on the secondconductive patterns and electrically connected to the first conductivepatterns; and a transparent resin covering the light emitting diode. 12.The light emitting diode package according to claim 11, wherein theboard body is made of one selected from a group consisting of aluminum,titanium, tantal, magnesium, halfnium and alloys thereof.
 13. The lightemitting diode package according to claim 11, wherein the insulatingoxidation layers are formed by anodizing.
 14. The light emitting diodepackage according to claim 11, wherein the insulating oxidation layershave a uniform thickness.
 15. The light emitting diode package accordingto claim 11, wherein the insulating oxidation layers are formed onsurfaces of the opposing edges of the board body including upper andlower surfaces and flank surfaces thereof.
 16. The light emitting diodepackage according to claim 11, wherein the insulating oxidation layersare formed such that both end portions thereof located in a top surfaceof the board body are extended toward a central line of the board body,which is substantially parallel with the opposing edges.
 17. A methodfor manufacturing a light emitting diode package comprising: perforatingat least two through holes in a board body made of a thermallyconductive metal; forming insulating oxidation layers in predeterminedareas of the board body, which are adjacent to upper and lower ends ofthe through holes, and inner wall surfaces of the through holes,respectively; forming first conductive patterns on the insulatingoxidation layers, respectively, and second conductive patterns betweenthe first conductive patterns; disposing light emitting diodes on thesecond conductive patterns between the through holes, respectively, andelectrically connecting the light emitting diodes with the firstconductive patterns; coating a transparent resin to cover the lightemitting diodes; and cutting the board body to separate the lightemitting diodes into each unit
 18. The method according to claim 17,wherein the through holes are formed in at least two rows in theperforating step, each of the insulating oxidation layers is formed tosurround the through holes in each of the rows in the step of formingthe insulating oxidation layers, and each of the light emitting diodesis disposed between two of the through holes in different rows in thestep of disposing the light emitting diodes.
 19. The method according toclaim 15, wherein the transparent resin is formed of a strip to entirelycover the rows of the light emitting diodes.
 20. The method according toclaim 15, wherein the insulating oxidation layers are formed byanodizing.
 21. The method according to claim 15, wherein the board bodyis made of one selected from a group consisting of aluminum, titanium,tantal, magnesium, halfnium and alloys thereof.